Thanks for the replies. The reason for my concern about Mg was because my java ferns were struggling. Digging around this and other forums it seemed that java ferns had a need for more magnesium and phosphate under higher lights. I checked my city water report and did a test and it appeared that there was plenty of calcium but no Mg.
With respect to N03 and K deficiencies, its hard to say what my ppm were, since i EI dose according to recommended levels and dont measure. BUT i was noticing pinholes in the java fern, anubias, and my stems were melting. I suspected a nitrate deficiency because leaves, especially on my anubias were turning yellow at the tip and slowly melting back. Also I had an outbreak of BGA.
As a result I upped my EI dosing and added MgS04. Im already noticing a huge difference. BGA has died back, any that i remove does not return. Java Fern has greened back up. Explosive growth on rotala colorata, rotala macandra ,rotala walichii and A. renkeii mini. Anubias greened up again from yellow. With respect to Magnesium I suspect that I may not need as much. I used only a 1tsp per dose as opposed to the 4tsp. So something went right here. I was thinking about slowly backing off one fert at a time and observe results but plants seem happy and I'm wondering if I'd need more ferts as plant mass expands. I'm thinking i'm going leave things as they are and keep watching.